Chemistry Grade 9

What are the 5 steps of the Scientific method?

observation, question Hypothesis, Results, conclusion

What do you do if the Hypothesis is not supported?

Make a new hypothesis then do the experiment again

What is an independent variable?

the thing that you can change

What is a dependent variable?

the thing you measure

What is a control variable?

The thing you keep the same

What are quantitative properties?

Quantitative properties are things using numbers to describe your experiment.

What are qualitative properties?

Qualitative properties are the things to describe the qualities of your object.

What are the three states of matter?

The three states of matter are solid, liquid, and gas.

What is it called when a solid turns into a liquid?

Melting

What is it called when a liquid turns into a solid?

Freezing

What is it called when a liquid turns into a gas?

Evaporation

What is it called when a gas turns into a liquid?

Condensation

What is it called when a gas turns into a solid?

Deposition

What is it called when a solid turns into a gas?

Sublimation

What are the five parts of particle theory?

1. All matter is made up of tiny particles.

2. Each pure substance has it's own particle

3. Particles are attracted to each other.

4. Particles are always moving.

5. At high temperetures, particles move faster

What is a physical property?

Something that can be seen/felt that doesnt change the substance.

What are some quantitative physical properties?

Melting point, Boiling point, Solubility, Hardness, Viscosity, Conductivity, Temperature, e.t.c

What are some qualitative physical properties?

Colour, State of Matter, Odour, Texture, Lustre (shiny), Malleability (bendability)

What is the difference between qualitative and quantitative physical properties?

Qualitative talks about the how it looks and feels and Quantitative talks about numerical data.

What is a chemical property?

A chemical property is how a substance changes into a new substance.

What are some Chemical Properties?

Reactivity with substances, Combustibility, Stability, Toxicity.

What is solubility?

Solubility is the substances ability to dissolve in water.

What is density?

Density is the mass of a substance over the volume it occupies.

How do you calculate density, mass, and volume?

Density = Mass/Volume

Mass = Density x Volume

Volume = Mass/Density

What does the G.R.A.S.P. method stand for?

G- Given R- Required A- Analysis S- Solve P- Predict

Whats the difference between a physical and chemical properties?

Physical properties doesn't change its compostition and reversable change. Chemical properties changes its compostion and makes a new substance.

What are the evidences of chemical changes (reactions)?

Formation of Gas, Formation of a solid, Odour or colour change, and Energy Productions.

What are the 3 subatonic particles?

Protons, Neutrons and Electrons.

What is the mass of each subatonic particle?

P= 1 amu N= 1 amu and E= insignificant amount.

What is the charge of each subatonic particle?

P= Positive N= Neutral E= Negative

What are Isotopes?

Isotopes are atoms that have the same number of protons but different numbers of neutrons making it have a different mass.

What was the dates of all of the people who discovered something about atoms?

1911, 1913, 1932

Who were the people who discovered something about atoms?

Rutherford, Bohr, Chadwick

What did Rutherford discover?

Ruthorford discovered that atoms have a positive nucleus in the center and electrons spinning around it.

What did Bohr discover?

Bohr discovered that electrons revolve around the nucleus in energy levels. He also discovered that a nucleus has protons inside.

What did Chadwick discover?

Chadwick discovered that the protons help make up the nuclei.

What was the man that organized the periodic table?

Dimitri Mendeleev

When did Mendeleev start organizing the periodic table?

1800s

What did Mendeleev discover?

Mendeleev noticed a pattern of properties in elements arranged by increasing atomic mass.

Which is the periods in the periodic table?

The horizontal rows

Which is the groups in the periodic table?

The vertical columns

What is the atomic number?

The atomic number is the number of protons in an atom and where it is on the periodic table.

What is the atomic mass?

Atomic mass is the sum of protons and neutrons in an atom.

What is standard atomic notation?

The top is the mass, the middle has the symbol and the bottom has the number.

What is the order of the energy rings?

2-8-8-2

What are the 3 types of metals?

metals, non-metals, metalloids

What are some things that describe metals?

Shiny, Good conductors of electricity, Malleable, a solid at room temp (except Mercury)

What are some things that describe non-metals?

Not shiny, poor conductors of electricity, some gases and some liquids at room temp

What are some things that describe metalloids?

Share some properties with metals (sometimes shiny and solids at room temp) share some properties with non-metals (brittle, poor conductors of electricity)

What are the 4 periodic groups?

Alkali metals, Alkaline earth metals, Halogens, and Noble gases

What are some things that describe Alkali Metals?

Low melting points, able to be cut with a knife, highly reactive (Almost the same with Halogens)

Which group is the Alkali Metals on the periodic table?

Group 1 to period 7

What are some things that describe Alkaline Earth metals?

reactive (not as reactive as Alkali metals), Burns in air, produces colourful flames

What are some things that describe Halogens?

Highly reactive (almost the same as Alkali metals) very corrosive (rusts) melting point increases as you go down the column

What are some things that describe Noble gases?

odourless, colourless, Gases at room temp, non-reactive,

Which group is the Alkaline Earth Metals on the periodic table?

Group 2 to period 7

Which group is the Halogens on the periodic table?

Group 17 to period 6

Which group is the Noble gases on the periodic table?

Group 18 to period 7

What is an ion?

An Ion is an atom with a positive or negative charge.

How does an atom become an ion?

An atom becomes an ion by having a full valence shell.

How do you know if its a positively charged ion and not a negatively charged ion?

If the ion has more protons then it has a more positive charge, it goes the same way with electrons.

What are the two types of ions?

cations and anions

What is a cation?

A positively charged ion

What is an anion?

A negatively charged ion

What is an ionic bond?

A chemical bond that's formed by the attraction of two oppositely charged ions which then become neutral. An ionic bond also transfers 1 or more electrons from an atom to another.

What is a covalent bond?

When 2 or more electrons are shared between the two atoms in a molecular compound. They are also attracted to each others positive nucleus resulting in a "tug of war".

What is a crystal lattice?

the formation of ions in a repeating pattern.

What are physical properties of an ionic compound?

An Ionic compound exists in a crystal lattice. They are also solid at room temperature, needs high temperatures to turn into a liquid, dissolves in water (seperating the positve and negative ions) they arent able to conduct electricity, and when dissolved into a liquid state the crystal lattice is broken making it able to conduct an electric current .

What is the difference between a covalent and an ionic bond?

A covalent bond are non-metals, remain unchanged, and form individual molecules. An ionic bond is metals and non-metals, has a positive or negative charge, and forms a crystal lattice.

What is a molecular compound?

A molecular compound is formed when 2 or more non-metal atoms share a pair of electrons to for a covalent bond.

How do you name molecular compounds?

1. Write the entire name of the first element

2. Change the ending on the second name to -ide

3. Use a prefix to indicate the number of each type of atom in the formula: the prefix is only used for the second element.

What is the criss cross method used for?

It's used for making the chemical formulas.

How do you do the criss cross method?

Write the symbols of the 2 elements then the ion charge goes to the other element. If charge has 1 than no need to put down. The metal always comes first.